Z-scheme Heterojunction Structure Research Articles

A direct Z-scheme polypyrrole/Bi2WO6 nanoparticles with boosted photogenerated charge separation for photocatalytic reduction of Cr(VI): Characteristics, performance, and mechanisms

Creating specific photoinduced carriers transport pathways is an important means of improving the photocatalytic performance. Here, we report a simple modification strategy: in-situ deposition of polypyrrole (PPy) onto Bi2WO6 (BWO) surface. The close contact between the interface of BWO and PPy as well as the appropriate band structure made it form a bult-in electric field, thus driving the direct Z-scheme charge transfer. The Cr(VI) reduction efficiency was 99.7% in 15 min under visible light irradiation, with the reduction rate constant reaching 0.221 min−1, which was about 19.2 times that of the bare BWO. The mechanism study showed that the Z-scheme heterojunction structure between PPy and BWO can effectively separate and transfer photogenerated charges, retain stronger redox ability of the system, and improve the photocatalytic performance. In addition, considering the complexity of the actual water environment, the effect of pH value and several substituted benzenes on the reduction of Cr(VI) were studied, and the relationship between the property and structure of substituted benzenes and Cr(VI) reduction rate were determined. We hope this work can provide a new sight toward designing a direct Z-scheme heterostructure and visible light photocatalytic activity of Cr(VI).

0D/2D/2D ZnFe2O4/Bi2O2CO3/BiOBr double Z-scheme heterojunctions for the removal of tetracycline antibiotics by permonosulfate activation: Photocatalytic and non-photocatalytic mechanisms, radical and non-radical pathways

• Efficient removal of TCs was achieved by the catalyst/sunlight/PMS systems. • The double Z-scheme heterojunction structure was proved by multiple characterizations and DFT calculation. • 1 O 2 was the dominant species for TCs degradation rather than SO 4 ·− or ·OH. • Photocatalytic and non-photocatalytic processes were distinguished. • Radical and non-radical pathways were also elucidated. A series of environmental-friendly and cost-effective 0D/2D/2D ZnFe 2 O 4 /Bi 2 O 2 CO 3 /BiOBr double Z-scheme heterojunctions (abbreviated as xZnCB) were fabricated by a hydrothermal method using an electrostatic self-assembly strategy. The removal efficiencies toward tetracycline (TC), oxytetracycline (OTC), and doxycycline (DOX) were 93%, 90.1%, and 89.4% in 10ZnCB/sunlight/permonosulfate (PMS) systems within 20 min, and the degradation rate constants of 10ZnCB were 5.7–8.2 times higher than those of ZnFe 2 O 4 and 2.6–2.9 times higher than those of Bi 2 O 2 CO 3 /BiOBr (CB) under the same conditions. XPS valence band spectra, quenching experiments, EPR measurements, and density functional theory (DFT) calculations demonstrated the existence of the double Z-scheme heterojunctions. The coexistence of radical and non-radical pathways caused by photocatalytic and non-photocatalytic degradation mechanisms was also elucidated. PMS was effectively activated by a photoinduced e − , · O 2 − , and Fe(II)/Fe(III) pathway, and active species including · O 2 − , 1 O 2 , SO 4 · − , · OH, and h + participated in the catalytic processes. Unexpectedly, 1 O 2 , and · OH were determined to be the primary species during the degradation processes instead of SO 4 · − . Recycling experiments, metal leaching measurements, and TC degradation experiments in the secondary effluent demonstrated the excellent catalytic and structural properties of these xZnCB hybrid materials.

Microbial coupled photocatalytic fuel cell with a double Z-scheme g-C3N4/ZnO/Bi4O5Br2 cathode for the degradation of different organic pollutants

A novel heterostructure of g-C3N4/ZnO/Bi4O5Br2 (ZB-3) was designed, and used in the microbial coupled photocatalytic fuel cell (MPFC). It can effectively improve electron utilization efficiency and pollutant degradation using this double Z-scheme heterojunction structure. The current–time (I–t) curves demonstrated that the current density of ZB-3 was higher than that of ZnO, ZnO/Bi4O5Br2 (ZB-1), g-C3N4/ZnO (ZB-2). Electrochemical impedance spectroscopy (EIS) indicated ZB-3 possessed the minimum charge-transfer resistance. This MPFC for degrading rhodamine B (RhB) and tetracycline (TC) under different conditions were developed using these materials. Even in the dark condition, MPFC with g-C3N4/ZnO/Bi4O5Br2 demonstrated 93% and 82% degradation efficiency for RhB and TC, respectively. Furthermore, the electron transport mechanism of the MPFC and ZB-3 were proposed. It paves the approach for more efficient pollutant degradation via MFC photocatalysis.

Oxygen-controlled photo-reforming of biopolyols to CO over Z-scheme CdS@g-C3N4

<h2>Summary</h2> Photocatalytic carbon monoxide (CO) production from biomass is a sustainable route for achieving the carbon-neutral goal, but the current catalytic activity is low. One of the reasons is that the reaction is thermodynamically unfavorable (ΔG >0) in inert atmosphere. The reaction can be transformed into thermodynamically favorable (ΔG <0) in an oxygen-rich atmosphere but it leads to the deep degradation to CO₂. Targeting this problem, we herein report an oxygen-controlled photo-reforming process to convert biomass-derived polyols into CO at room temperature. A CdS@g-C₃N₄ composite shows 48% yield of CO from glycerol in an appropriate O₂ atmosphere, which is 13-fold of that in inert atmosphere. The Z-scheme heterojunction and core-shell structure of CdS@g-C₃N₄ not only efficiently promote charge separation and the enrichment of photogenerated electrons on the g-C₃N₄ shell but also facilitate the adsorption and activation of dioxygen. This study provides a new oxidative photo-reforming strategy to produce CO from biomass under mild conditions.

Oxalic acid modified hexagonal ZnIn2S4 combined with bismuth oxychloride to fabricate a hierarchical dual Z-scheme heterojunction: Accelerating charge transfer to improve photocatalytic activity

Multivariate organic acids can modify the structure and morphology of materials to some extent. In this work, the addition of oxalic acid can make the morphology of ZnIn2S4 become uniform, the crystal structure of ZnIn2S4 can change from cubic to hexagonal, and the photocatalytic activity was improved. The dual Z-scheme ZnIn2S4/BiOCl heterojunction was successfully fabricated by a two-step hydrothermal-hydrolytic method. The concept of green chemistry was used to make full use of thiourea, and the rapid decomposition of Rh B and TC was realized by ZIS/BOC-8 under visible light in a shorter period time than other photocatalysts in this system. In order to investigate the relationship between the structure and properties of the catalyst, XRD, FT-IR, SEM, HRTEM, UV–vis DRS, XPS and other characterization technologies were used to analyze the structure, morphology, optical properties of the samples, showing that ZnIn2S4/BiOCl have been successfully synthesized indicates the existence of Z-scheme heterojunction structure. PL, TRPL and EIS analysis showed that the Z-scheme heterostructures could rapidly promote the separation of holes and photo-induced electron carriers, enhancing the photocatalytic performance and stability. The photocatalytic degradation results showed that the degradation rate of Rh B and TC by ZIS/BOC-8 were more than 92% within 30 min, comparing with other catalyst, ZIS/BOC-8 showed preferable visible light catalytic degradation activity, and the order of catalytic activity was as follows: ZIS/BOC-8 > BiOCl-S > BiOCl, ZnIn2S4. Moreover, the degradation pathway of Rh B was discussed by 3D-EEM and LC-MS, and the photocatalytic mechanism of the system was proposed, especially the mechanism of photocatalytic degradation of Rh B by ZIS/BOC under visible light.

Phosphorus-doping CdS@NiFe layered double hydroxide as Z-Scheme heterojunction for enhanced photocatalytic and photo-fenton degradation performance

A novel P-doping CdS [email protected] layered double hydroxide (LDH) Z-scheme photocatalyst ([email protected]) is synthesized through hydrothermal and calcination strategies. Phosphorus doping could form a new Fermi level and reduce the intermediate band gap, thereby prolonging the lifetime of photo-generated electron carriers. The well-designed core–shell nanostructure is conducive to the rapid transfer of carriers. The formation of Z-scheme heterojunction can provide a higher redox potential and reduce the photo-corrosion phenomenon of CdS. The prepared 20% wt [email protected] sample exhibits the highest hydrogen generation rate, which is about 39 times higher than that of the pristine CdS sample. In addition, the degradation rate of [email protected] photocatalyst on bisphenol A is about 98% within 160 min irradiation. With the addition of H2O2, the photocatalytic degradation performance can be improved significantly due to the photo-Fenton reaction. The excellent catalytic performance can be attributed to the synergistic effect of P-doping and Z-scheme heterojunction extending the photoresponse and promoting spatial charge separation. This research provides a new perspective for the design and synthesis of other Z-scheme heterojunction structure photocatalysts.

Dual-functional Z-scheme CdSe/Se/BiOBr photocatalyst: Generation of hydrogen peroxide and efficient degradation of ciprofloxacin

The major challenges of clean energy and environmental pollution have resulted in the development of photocatalysis technologies for energy conversion and the degradation of refractory pollutants. Herein, a novel CdSe/Se/BiOBr hydrangea-like photocatalyst was used to produce hydrogen peroxide (H2O2) and degrade ciprofloxacin (CIP). The Z-scheme heterojunction structure of the photocatalyst and the doping of selenium (Se) led to the efficient separation of electron-hole pairs and charge transfer. The optimized sample of 2 wt% CdSe/Se/BiOBr produced 142.15 mg·L−1 rate of H2O2, which was much higher than that produced by pure BiOBr (89.4 mg·L−1) or CdSe/Se (10.9 mg·L−1). Additionally, almost 100 % of CIP was degraded within 30 min, with a first order rate constant of nearly 5.35 times that of pure BiOBr and 81.44 times that of pure CdSe/Se. The excellent removal efficiency of CIP from natural water matrices confirmed that the composites are promising for the removal of contaminants from natural waterways. Based on trapping experiments, electron spin resonance spectra (ESR) spectroscopy, and density functional theory (DFT) calculations, the photocatalytic mechanisms of H2O2 and CIP degradation by the Z-scheme CdSe/Se/BiOBr composites were proposed. Overall, the dual-functional CdSe/Se/BiOBr composite could potentially be applied for photocatalytic production of H2O2 and treatment of organic pollutants in water.

2D/2D g-C3N4/TiO2 with exposed (001) facets Z-Scheme composites accelerating separation of interfacial charge and visible photocatalytic degradation of Rhodamine B

Z-scheme heterojunction was successfully constructed with (001)-TiO2 and g-C3N4 via electrostatically self-assemble. Z-Scheme heterojunction nanocomposites improve separation efficiency of photogenerated e−-h+ pairs, which strengthen visible photocatalytic elimination for Rhodamine B. The g-C3N4 with narrower bandgap not only forms a stable phase interface with (001)-faceted TiO2 nanosheets, but also provides high productivity of photo-excited charge carries. Meanwhile, the layered graphite carbon in g-C3N4 owns an excellent ability to transfer electrons. The RhB degradation rate of the g-C3N4/(001)-faceted TiO2 hybrid reach up to 99.9% under the visible light for 2 h. This study provided an efficient g-C3N4/(001)-faceted TiO2 photocatalyst with Z-Scheme heterojunction structure has emerged as a promising approach to perfect the photocatalytic capacity of photocatalysts.

Fabricating Bi2MoO6@Co3O4 core–shell heterogeneous architectures with Z‑scheme for superior photoelectrocatalytic water purification

The decomposition efficiency of refractory organic contaminants depends strongly on the characteristics of photoanode semiconductors during the photoelectrocatalytic (PEC) process, and selecting an excellent material with superior PEC efficiency is a challenge for the current PEC oxidation technique's practical application. Herein, a novel Bi2MoO6@Co3O4 hierarchical core–shell heterogeneous photoanode is fabricated by the simple hydrothermal process. Moreover, the amount of Bi2MoO6 nanosheets adhered to the surface of the Co3O4 nanowire can be easily tuned by changing the concentration of the Bi2MoO6 precursor solution. The as-prepared Bi2MoO6@Co3O4 photoanode exhibited larger electroactive surface area, lower charge transfer resistance, more negative flat band potential, and high separation efficiency of induced e-/h+ pairs, as compared with that of bare Co3O4 nanowire. It is worth mentioning that the Z-scheme heterojunction structure formed by the combination of Bi2MoO6 and Co3O4 maintained the more vital redox ability of induced e-/h+. Consequently, the as-prepared Bi2MoO6@Co3O4 photoanodes showed better PEC performance than Bi2MoO6 or Co3O4 for the degradation of reactive brilliant blue KN-R. The optimized Bi2MoO6@Co3O4-2.0 exhibited the highest degradation rate of 88.43% and accelerated stability of 110 min at the current density of 500 mA·cm−2 in 1.0 mol·L-1 H2SO4 solution. The strategy of fabricating core–shell heterostructure Bi2MoO6@Co3O4 photoanode with superior PEC efficiency may guide other heterogeneous designs.

Efficient photocatalytic H2 evolution and Cr(VI) reduction under visible light using a novel Z-scheme SnIn4S8/CeO2 heterojunction photocatalysts

Semiconductor photocatalysis technology is a promising method for hydrogen production and water pollution treatment. Here, the SnIn4S8/CeO2 (SISC) composites were fabricated by a stirring and calcination method, and the mass ratio of SnIn4S8 to CeO2 was optimized. The 50 wt% SISC heterojunction photocatalyst has the highest visible light catalytic activity. The degradation rate of hexavalent chromium (Cr (VI)) is 98.8% in 75 min of light irradiation, which is 2.48 times that of pure CeO2. Besides, the 50 wt% SISC composite photocatalyst also has the highest photocatalytic hydrogen production efficiency (0.6193 mmol g−1 h−1), which exhibits a higher photocatalytic activity than pure CeO2 and SnIn4S8. The enhanced photocatalytic performance can be attributed to the Z-scheme heterojunction structure between CeO2 and SnIn4S8, which can effectively separate and transfer photo-generated charges, thereby reducing the recombination of photo-generated carriers. We hope this work can provide ideas for constructing Z-scheme heterojunction structures and improving photocatalytic activity under visible light.

Construction of direct Z-scheme photocatalyst by the interfacial interaction of WO3 and SiC to enhance the redox activity of electrons and holes

The direct Z-scheme heterojunction structure benefits separation and migration of photoinduced carriers while maintaining original redox ability of each component. Nowadays, most Z-scheme structures are fabricated by g-C3N4 with other narrow band photocatalysts due to its low conduction band (CB). In this paper, SiC, another kind of photoelectric semiconductor with low CB, was employed to prepare direct Z-scheme photocatalyst with 2D WO3 by simple water oxidation precipitation method. The component and interface band structure of Z-scheme heterojunction WO3/SiC (WS) were verified by XPS, KPFM, Mott-Schottky method. The photodegradation efficiency and rate constant values of WS-1 for degrading RhB enhanced 2.5 and 5.3 times respectively compared with pristine WO3. Radical capture experiments and ESR tests affirmed that WS-1 photocatalyst produced •OH and •O2－active species, which further confirmed the photogenerated carriers were transmitted through the Z-scheme mode in principle. Band structure investigation showed that the direct Z-scheme structure assembled by WO3 with high valence band (VB) and SiC with low CB could maintain the high photocatalytic activity of active species. Therefore, this study offers a feasible method for construction of a novel and efficient direct Z-scheme photocatalyst.

Construction of core-shell ZnS@In2S3 rhombic dodecahedron Z-scheme heterojunction structure: Enhanced photocatalytic activity and mechanism insight

Photocatalytic degradation of organic pollutants was one of the significant ways to solve the problem of antibiotic pollution in the environment. In this work, the core-shell structure of ZnS@In2S3 rhombic dodecahedron (ZnS@In2S3 RD) Z-scheme heterojunction was synthesized. The In2S3 shell wraps the ZnS core, close coaxial contact and effectively promote the separation of electrons and holes through the In-S-Zn bond, and the redox ability of the In2S3 and ZnS RD could be maintained crediting to the Z-scheme system heterojunction. Marvelously, 100 mL, 20 mg/L TC-HCl solution can be completely degraded within 20 min, and the apparent reaction rate constant reaches 0.284 min−1 that far exceeds majority of the previously reported sulfide photocatalyst. Notably, the Finite Element Method (FEM) based on Comsol software was used to simulate the electric field distribution to verify the electric field enhancement effect caused by ZnS@In2S3 RD at the interface. In addition, the intermediate products of the photocatalytic degradation process were monitored by HPLC-MS to understand the degradation pathways. Finally, a possible photocatalytic degradation mechanism was proposed through experimental results and theoretical analysis. This work provides a reference for the development of efficient antibiotic photodegradation catalysts.

Photocatalytic degradation of diclofenac using TiO2-CdS heterojunction catalysts under visible light irradiation.

The present study reports the photocatalytic degradation of analgesic drug diclofenac using the hydrothermally prepared TiO2-CdS heterojunction catalyst. The results suggest that the prepared catalysts exhibited excellent photocatalytic activity under visible light irradiation. The photodegradation kinetics were well fitted to the pseudo-first-order reaction. The apparent reaction rate constant for TC5 catalyst in the diclofenac degradation was 0.02316min-1. Mineralisation of diclofenac using TC5 photocatalyst was around 86% within 4h of irradiation time. The operating parameters such as optimal catalyst dosage, apparent solution pH and the effect of initial diclofenac concentration were also studied using the TC5 catalyst. The role of active species in the degradation mechanism was elucidated and it was found that the hydroxyl radical is the main active species in the diclofenac degradation mechanism. The charge transfer between heterojunction catalysts is facilitated by direct Z-scheme heterojunction structure. The coupled photocatalysts also showed good photochemical stability and reusability over five successive reaction cycles. The tentative degradation pathway has been devised based on LC-MS peaks, and it is found that only m/z 224, m/z 178 and m/z 124 were persisted at the end of the reaction.

Antimonene Nanosheets-Based Z-Scheme Heterostructure with Enhanced Reactive Oxygen Species Generation and Photothermal Conversion Efficiency for Photonic Therapy of Cancer.

A Z-scheme heterojunction with high separation efficiency of photogenerated electrons and holes and enhanced reduction/oxidation potentials, which can enhance reactive oxygen species generation and photothermal conversion efficiency, exhibits tremendous potential in photonic theranostics. Herein, antimonene nanosheets (Sb NSs) are functionalized with photosensitizer 5,10,15,20-Tetrakis(4-hydroxy-phenyl)-21H,12H-porphine (THPP) and a poly(ethylene glycol) (PEG) modifier. The Sb-THPP-PEG NSs thus fabricated are found to form a Z-scheme heterojunction structure between Sb and THPP, based on their valence band and bandgap level analysis. The Z-scheme heterojunction structure enables the Sb-THPP-PEG NSs multiple promising features for cancer therapy. Firstly, due to improved electron-hole pairs separation efficiency and redox potential, new reactive oxygen species •O2- is generated, besides the production of 1 O2 by THPP. Secondly, the assembly of THPP enhances the NIR-light-to-heat conversion of Sb NS, a photothermal conversion efficiency as high as 44.6% is obtained by this Sb-THPP-PEG NSs photonic nanomedicine. Moreover, the photothermal, fluorescent, and photoacoustic imaging properties of Sb-THPP-PEG NSs allow multimodal imaging-guided tumor treatment.

Direct Z-scheme SnO2/Bi2Sn2O7 photocatalyst for antibiotics removal: Insight on the enhanced photocatalytic performance and promoted charge separation mechanism

A kind of direct Z-scheme SnO2/Bi2Sn2O7 heterojunction photocatalyst was fabricated aiming to explore the underlying photocatalyitc mechanism as well as the improved photocatalytic antibiotics degradation activity. Experimental results indicated that the existence of the built-in electric field between SnO2 and Bi2Sn2O7 led to a direct Z-scheme charge transfer. The efficient separation and fast transfer of photogenerated charge carriers contributed to boosting the photocatalytic performance of SnO2/Bi2Sn2O7. The optimal photocatalytic tetracycline degradation efficiency of SnO2/Bi2Sn2O7 was 88.4 %, which was 1.4-fold higher than that of pure Bi2Sn2O7 (62.9 %) and 12.5 times higher than pure SnO2 (7.1 %). Radical trapping experiments and electron paramagnetic results indicated that the photocatalytic degradation process in SnO2/Bi2Sn2O7 system was modulated by photogenerated electrons, holes and O2− active species. This work may offer a new insight for enhancing the photocatalytic activity of Bi2Sn2O7 by constructing a direct Z-scheme heterojunction structure.

Depositing Ag2S quantum dots as electron mediators in SnS2/g-C3N4 nanosheet composites for constructing Z-scheme heterojunction with enhanced photocatalytic performance

The novel Z-scheme heterojunction photocatalyst g-C3N4/Ag2S/SnS2 with Ag2S quantum dots as electron mediators was successfully synthesized by in-situ ion exchange reaction and self-peeling of g-C3N4. Compared with g-C3N4, SnS2 or g-C3N4/SnS2, the photocatalyst g-C3N4/Ag2S/SnS2 exhibited more excellent photocatalytic performance under visible light irradiation. The removal rate of methyl orange was 96.8% after 30 minutes visible light irradiation and the reaction rate constant reached 0.10225 min-1. The enhanced photocatalytic activity could be attributed to the formation of Z-scheme heterojunction structure and the 2D layered structure. The electrochemical and photoelectric performance tests showed that the separation and transfer efficiency of the photogenic electron-hole pairs as well as the redox potential were significantly improved. Additionally, the quenching experiments showed that the superoxide radicals and holes were the primarily active species. Combined with other characterizations, the reaction mechanism of the g-C3N4/Ag2S/SnS2 for degrading the target pollutant methyl orange under visible light irradiation was proposed.

Efficient photocatalytic hydrogen production using an NH4TiOF3/TiO2/g-C3N4 composite with a 3D camellia-like Z-scheme heterojunction structure

Photocatalysis is one of the most promising ways to realize artificial photosynthesis. The biologically inspired photocatalysts with 3D flower-like structures have attracted much attention. In this study, an effective method for the synthesis of composite photocatalytic material, NH4TiOF3/TiO2/g-C3N4, with a 3D camellia-like structure, was developed. The 3D hierarchical structure of the composite material enabled multiple refractions and reflections of light within the catalyst, which greatly improved the efficiency of the sunlight harvesting. The combination of NH4TiOF3 and TiO2 also effectively reduced the electron-hole recombination in the g-C3N4. To evaluate its photocatalytic performance, the prepared nanostructured composite materials were tested for the water-splitting with simulated sunlight. It showed the hydrogen evolution at the rate of 3.6 mmol/g/h, which is 4.0 times faster than that from the pure g-C3N4. The composite materials exhibited excellent cycling stability. The detailed mechanism of the Z-scheme heterojunction was also discussed. The proposed synthesis route for the creation of 3D flower-like hierarchical composites provides a new effective technique for developing efficient, active, and stable composite photocatalysts for hydrogen production.

Novel Z-scheme W18O49/CeO2 heterojunction for improved photocatalytic hydrogen evolution

The novel Z-scheme heterojunction photocatalyst W18O49/CeO2 was prepared by hydrothermal synthesis. The photocatalytic properties of W18O49/CeO2 were evaluated by photocatalytic hydrogen evolution under visible light. The result shows that the 15 wt% W18O49/CeO2 composite has the best hydrogen production efficiency of about 0.2061 mmol g-1h−1, which was 1.93 times higher than that the obtained pure CeO2. The characterization results demonstrated that the existence of Z-scheme heterojunction structure at the contact interface of W18O49 and CeO2 was the origin of the enhanced photocatalytic performance for hydrogen evolution, which could greatly increase the accumulation of photo-generated electrons and the separation efficiency of charge carrier. In accordance with density functional theory (DFT) calculation, we further confirmed the formation of Z-scheme heterojunction structures. This work is anticipated to expand the ideas for modifying CeO2 semiconductor materials to improve the rate of photocatalytic hydrogen production.

Improvement of antibacterial activity of hydrothermal treated TC4 substrate through an in-situ grown TiO2/g-C3N4 Z-scheme heterojunction film

Abstract In-situ growth of a TiO2/g-C3N4 film with Z-scheme heterojunction structure on the hydrothermally treated titanium alloy via a calcination approach was firstly demonstrated in this work. Compared with the hydrothermally treated substrates, the as-prepared samples showed good hydrophilicity and osteoblast-like cell proliferation, evidencing their potential for improving the biocompatibility and osteogenesis of titanium alloy. Subsequently, more than 65% of E. coli was reduced on the surface of TiO2-g-C3N4 film under natural sunlight, indicating an enhanced antibacterial activity. The noticeably improvement of the antibacterial performance was ascertained mainly due to the presence of Z-scheme heterojunction between TiO2 and g-C3N4. Such structure could not only improve the separation and transfer of photogenerated carriers, but also increase the number of photogenerated electrons, thus enhancing the yielding of reactive oxygen species (ROS) to kill bacteria.

Synthesis of direct Z-scheme ZnIn2S4@BiOBr-(110) heterojunction structure with high photocatalytic activity

In this article, the novel direct Z-scheme ZnIn2S4@BiOBr-(110) heterojunction structure was firstly synthesized via simple two-step hydrothermal method. The results of XRD and HRTEM indicated that as-prepared BiOBr mainly exposed high energy (110) facet. Simultaneously, the photoelectrochemical measurement was performed to further investigate the photo-induced carrier separation efficiency. The results indicated that Z-scheme heterojunction structure formed by the loading of ZnIn2S4 nanosheets not only promoted the separation of photogenerated carriers and inhibited fast recombination rate of photogenerated electron–hole pairs of pure BiOBr, but also endowed the composite with better redox activity. The degradation efficiency of RhB by BiOBr loaded with 10 mol% ZnIn2S4 has achieved 98% within 18 min under the irradiation of Xe lamp, which demonstrated that the unique direct Z-scheme ZnIn2S4@BiOBr-(110) composite photocatalytic materials has the potential application in environmental pollution control and energy conversion.